It is sometimes desired to abstract parts of text or image information in a document which may later be edited using appropriate software in a computer. A known method of inputting text and image information into a computer is to use a stationary or portable scanner.
A stationary scanner is suitable for entering entire pages with text and image information, the scanner being automatically passed across the page at a constant speed. This type of scanner is not suited for inputting selected parts of information on a page.
A portable, handheld scanner may be used any time interesting information is to be scanned, but normally has a limited field of view.
U.S. Pat. No. 5,301,243 discloses a hand-held scanner for reading characters from a string of characters on a substrate. The scanner is moved in contact with the substrate along the character line and has an optical system which images a small part of the substrate. The optical system comprises a CCD type line sensor provided with a plurality of light-sensitive elements arranged in a line. When the scanner is passed across the characters on the substrate, a succession of vertical slices of the characters and of the spaces between them is recorded. The slices are stored in the scanner as a digital bit-map image. OCR software (OCR=Optical Character Recognition) is then used to identify the characters and store them in character-coded form, such as ASCII code. The character recognition can be made either in the scanner or in an external computer to which the bit-map image is sent.
Another type of hand-held scanner for inputting text is disclosed in U.S. Pat. No. 4,949,391. This scanner has a two-dimensional sensor which records images of the underlying surface as the scanner is being moved across the same. The scanner is restricted to movements in a direction which is determined by a wheel in contact with the surface. Before the recorded images are assembled into a composite image, redundant information is removed from the images. The composite image can be analyzed in a computer for identification of characters.
A drawback with the handheld scanners described above is that their field of view is relatively small. In order to record a large amount of information, such as passages consisting of several lines, a user must therefore move the scanner back and forth across the surface repeatedly. Moreover, the movement has to follow a predetermined path, such as along the lines of text.
Publication WO 99/57675 discloses a device for recording information from a substrate The device may operate in two modes, one scanner mode, in which lines of text is scanned, and a photograph mode, in which separate pictures are taken of a document or an object.
Publication WO 98/20446 discloses a scanner pen, which is adapted to be moved over a line of text for scanning the text. As the pen moves over the text image, several pictures are taken of the text. The pictures are processed by a computer and assembled or stitched together for forming a composite image of the entire line of text, which cannot be read by a single picture. The scanner pen can only scan a single line of text at each time.
Thus, there is a need for a handheld scanner pen of the above-mentioned type which is adapted to scan several lines of text simultaneously as well as smaller pictures.